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I've been running my track car (To4E) without the aux water pump. I pulled apart my turbo a few weeks ago to inspect it and refresh the bearings and ceramic coat the hot side and down-pipe. It was fine. There was some coking under the turbine to CHRA heat shield and some slight varnishing on the shaft but it has cleaned up just fine and has no noticeable play.
I replaced the CHRA due too an unrelated issue. Also worthy of note is that the turbo specialist who rebalanced it for me noted that I had been running an oil restrictor and his advice was to not use a restrictor from now on.
I've been running a dry turbo for years at 18 to 20 psi, no difference. Block off plate at the pump and changed to a NA coolant tank. I just allow extra warm up and cool down time. Sure does reduce clutter up front
Another thing to consider in the "battle between simplicity and durability" is the OE presence of a 110 deg.C thermoswitch (near the turbocharger) for the pump. It could come in handy during a race.
I deleted it on my track car. Since the rebuild about a year ago, I've only driven it on the street, breaking it in, so I have no results to share, but I agree that it's not worth the clutter. I did keep the water cooling lines; I replaced the aux pump with this thing:
I've been running my track car (To4E) without the aux water pump. I pulled apart my turbo a few weeks ago to inspect it and refresh the bearings and ceramic coat the hot side and down-pipe. It was fine. There was some coking under the turbine to CHRA heat shield and some slight varnishing on the shaft but it has cleaned up just fine and has no noticeable play.
I replaced the CHRA due too an unrelated issue. Also worthy of note is that the turbo specialist who rebalanced it for me noted that I had been running an oil restrictor and his advice was to not use a restrictor from now on.
Did you keep the rest of the turbo water system or did you completely block it off?
Another thing to consider in the "battle between simplicity and durability" is the OE presence of a 110 deg.C thermoswitch (near the turbocharger) for the pump. It could come in handy during a race.
Laust
Not sure I follow what you mean?
Has anyone noticed if the pump actually runs during hard driving?
Assuming that the Turbo thermostat is open but the turbo water pump is not running (turbo termo switch not triggered), which should be the most common state when driving.
Looking at the picture from Clarks Garage the water will flow from the expansion tank thru the turbo if the underpressure created by the main water pump is sufficient (the water should then also flow in the opposite direction of the arrow on the red line between the turbo and the expansion tank).
Will the water flow thru the turbo be very limited in this case?
Another thing to add to my previous comment, which is only intended as sharing my experience. Not claiming anything is right or wrong..... Deciding to go to a dry turbo for me happened while replacing and flushing my coolant lines one day. I had been driving my 951 for years, knowing the auxiliary pump was dead, or so I thought anyhow, but never having issues I never worried about it knowing the car pumped coolant through when the engine was running. So one day a had a stock hose burst, blasting coolant every where. Sure enough my 20 something year old hoses were all getting soft and we're due to change. So I bought a new hose kit and changed them all and when I did I discovered that my auxiliary pump relay was plain missing and a even bigger suprise the plastic port connection at the water pump that cools the turbo had never been drilled by the PO. So unknown to me, I had been driving the car for 30,000+ miles with the turbo never getting coolant and never had any issues. So after accidentally running the turbo dry for that long and never having issues I decided to just remove it all and reduce the cooling systems leak points. Having since upgrading my car, I now run a LR super 65 turbo with a p-trim hot housing. I run 18 to 22 psi. Never had a coolant issue or any hot oil issues. Turbos still as good as new, years later. After tearing apart a few engines now, I've found that a lot of people forget or don't know that the plastic fitting on the pump, when brand new, does not have an access hole through it and has to be drilled to be used ( designed this way to be a block off plate for NA cars ). Because of this many turbo owners have blocked off fittings installed on their cars from their last pump change and are unaware. So chances are if you had a mechanic do a water pump for you, unless they are very familiar with 944s, they wouldn't have known to drill it out either. So you may have a dry turbo already ...... Furthermore, if you are having heating issues, it's more likely that you have an issue with a thermostat, fan relay, or the thermo switch in the radiator, or possibly just air in the system. Youd be surprised how much your temp will rise if one or both fans are not working properly. I once had a 944 where the temp would always rise ever so slightly, enough to notice it's high but not too high and after trying everything I found that my left low speed fan didn't work. So the right one didn't cool the car enough and then the temp would rise and then the high speed relay would kick on and bring the temp back to normal. Anyways, just my 2 cents. With or without the pump you'll be fine if the car is healthy elsewise.
04-15-2017, 11:01 AM
Removing auxillary turbo water pump?
...... Furthermore, if you are having heating issues, it's more likely that you have an issue with a thermostat, fan relay, or the thermo switch in the radiator, or possibly just air in the system. Youd be surprised how much your temp will rise if one or both fans are not working properly. I once had a 944 where the temp would always rise ever so slightly, enough to notice it's high but not too high and after trying everything I found that my left low speed fan didn't work. So the right one didn't cool the car enough and then the temp would rise and then the high speed relay would kick on and bring the temp back to normal. Anyways, just my 2 cents. With or without the pump you'll be fine if the car is healthy elsewise.